Building arbor for tires and like articles having inextensible bead rings

ABSTRACT

A simple low cost building arbor having a wide range of axial length or bead set length variation. The arbor has no moving parts which are not of rubber or rubber-like material and is operable by air pressure alone. An expandable ring expands, by air pressure, to hold a bead ring in axial position and independently a turn-up bladder is expanded to turn a ply sleeve end about the bead ring. Operating air is conducted, in all axially selected positions in the range, not by tubing but by air transfer chambers connecting the bladder and a sleeve associated with the expandable ring with passage in the center shaft. 
     The present invention relates to a building arbor for tires and like articles. 
     The principal object of the invention is the provision of a simple, low cost building arbor actuable solely by fluid pressure to position an inextensible bead ring about a ply in cylindrical form on the arbor and to turn the ply ending about the bead ring. Broadly, the objects of the invention are accomplished in a building arbor comprising a center shaft having passages for conducting fluid, a pair of end rings axially slidable on the center shaft and having axially elongated annular air transfer chambers, the chambers being in air flow communication, respectively, with said passages and with a plurality of inflatable members affixed to each of the end rings, each of the members being expandable by fluid pressure in the respectively associated passage independently of another of said members in any selected axial position of the respectively associated end ring. 
     Briefly, the objective of the invention is accomplished also by a building arbor having a fixed nonexpandable building surface and a pair of expandable beadseating rings located respectively at the axial ends of the building surface, said beadseating rings being mounted respectively in unitary assemblies each including a primary ring, and means for adjustably fixing the axial distance between the two end rings comprising a pair of semi-cylindrical shells of selected axial length axially abutting each end ring and supported coaxially of the arbor by said end rings. 
     To acquaint persons skilled in the most closely related arts certain preferred embodiments illustrating the best mode now contemplated of putting the invention in practice are described hereinbelow making reference to the attached drawings forming a part of the description and of this specification.

In the drawing:

FIG. 1 illustrates an embodiment of a building arbor in accordance withthe invention;

FIG. 2 illustrates a further embodiment of a building arbor inaccordance with the invention.

A building arbor 10, FIG. 1, in accordance with the invention has acentral shaft 12 which is solid except for three passages 14, 16, 18parallel to the rotation axis 20 of the shaft. The smooth exteriorcylindrical surface 22 of the shaft extends axially equidistantlyoutward of a midplane 24 normal to the axis. At the supported end of theshaft, it is disposed snugly in the axial bore of a collet 26 having aflange 28 adapted for mounting on a building machine spindle (not shown)which is provided with means for delivering two independently controlledsupplies of compressed air. The end of the collet is splitlongitudinally to provide a compression clamp 33 securing the shafttherein and with a plurality of cap screws 35 which fix the shaftaxially relative to the flange.

At the free end of the shaft remote from the collet a shaft end piece 42fitted in a recess 43 concentric in the shaft accommodates a hardenedcenter 44 having a passage 46 axially therethrough which communicateswith a space 48 between the end piece and the bottom of the recessconnecting the passage 46 in the center 44 with the first 14 of thepassages in the shaft 12. The arrangement provides for support by aconventional live center at the free end of the shaft as well as forconnecting vacuum or air pressure to the arbor by way of the port 51.

A ring 53 is mounted on the shaft symmetrically with the midplane 24,held by the dog point screws 55 which engage the locating holes 57 inthe shaft. A center locating rib 59 extending circumferentially aboutthe ring 53 and radially outward from its circumference registers in aconjugate circumferential groove 62 formed in the radially inner surfaceof the cylindrical wall member 64 as to locate the member symmetricallywith respect to the plane 24.

The cylindrical surface of the wall member 64 has a suitable number ofsmall perforations communicating with the interior space 65. Air can bedelivered under pressure to or exhausted by vacuum from the space 65 byway of the port 51 and passage 14, and the pressure difference betweenthe surrounding atmosphere and the space 65 thus be applied to a tirecarcass or other flexible sleeve disposed on the arbor.

The member 64 comprises a pair of semi-cylindrical shells 64a, 64b whichare selectively interchangeable to provide different working lengths ofthe arbor as presently will appear. The axial ends of the shells abutrespectively a pair of split clamp rings 66 and are supported radiallyby the respective primary end rings 68 to which the clamp rings arerigidly secured. The cylindrical surfaces of the clamp rings and of theshells are at equal radial heights from the axis and cooperate toprovide the cylindrical working surface of the arbor between a spacedapart pair of annular recesses 71.

In each of the annular grooves a gum rubber beadseating ring 73 isdisposed coaxially of the shaft. In the radially outer surface of eachof the rings 73 is a bead set groove 75 the axially outer wall 75' ofwhich is formed by the axially inner edge portion 77 of a turnup bladder79. Each of the beadseating rings 73 is joined integrally with theinward edge portion 77 of the respective turnup bladder. The radiallyouter surface 79' of the turnup bladder for at least a portion of itsaxial length extends outward from the ring 73 at the same radial levelas the surface of the wall 64 and of the clamp rings 66.

The inward edge portion of each bladder is supported by a split clampring 82 which is secured rigidly to the respective primary end ring 68.

An expansion sleeve 84 of gum rubber or the like extends axially acrosseach recess 71 as well as circumferentially thereof and supports theseating ring 73 in its contracted condition as illustrated in FIG. 1.

Between the bottom of the recess 71 and the expansion sleeve 84 achamber 86 is formed which communicates by way of a port 88 in the endring 68 and the air transfer chamber 91 provided by the annular spacebetween the inner circumference of the end ring 68 and the cylindricalsurface 22 of the shaft, and thence by way of the shaft port 93 to thesecond 16 of the passages in the shaft 12. The arrangement enables thebeadseating ring 73 to be expanded by compressed air admitted into thechamber 86 in the end ring beneath the expansion sleeve 84. It isparticularly to be noted that this expansion of the ring 73 is not onlyeffected solely by fluid pressure rather than by mechanical linkage butis also controlled completely independently of the actuating compressedair for the turnup bladder 79 itself, about to be more fully described.

Moreover, to effect a rotation of the axial cross-section, that is, agreater expansion of the ring 73 axially inward of an inextensible beadtherearound than the expansion axially outward of the bead, a preferredarrangement of the ring 73 and sleeve 84 is employed. The sleeve 84,being fixed at each of its edges in the recess 71, tends to expand toits greatest extent at its own midplane, which is its plane of maximumelongation, circumferentially. The beadseating ring 84 tends to beelongated circumferentially at different rates or by differing amountsbetween its axial edge close to the ring 66 and its other edge attachedto the bladder 79. In order to accomplish such rotation the plane ofmaximum circumferential elongation of the sleeve 84 is offset axially ofthe beadseating ring 73 a small but sufficient amount, about 5millimeters. The degree of such rotation can also readily be varied byminor alteration of the cross-section shape of the ring 73, of thesleeve 84, or of the amount of offset.

The turnup bladders 79 each terminate in a pair of circumferentialflanges 79a, 79b and are supported radially by the end ring 68. Theflanges are spaced apart by the channel rings 95 in which a radialpassage provides for airflow communication between the bladder 79, theair passage 97 in the end ring, the air transfer chamber 99 formedbetween the bladder support sleeve 102, the end ring 68 and the shaft12, and by way of the shaft port 104 to the third longitudinal passage18 in the shaft. As previously indicated, this arrangement permits theactuation of the turnup bladder 79 independently of the actuation of thebeadseating ring 73.

The flanges 79a, 79b of each bladder are clamped respectively betweenthe channel ring 95 and the split lock ring 82 and between the ring 95and the bladder support sleeve 102 which is disposed slidably on thesmooth cylindrical surface 22 of the shaft. Each bladder support sleeveis provided with longitudinal grooves 102a giving access to the capscrews 106 which connect the sleeve to the respective primary end ring68 and effect clamping of the bladder flanges. In the interior of eachsupport sleeve is a circumferential land 108 having a seal, such as anO-ring, which seals the transfer chamber 99 to its axially outer end.The primary end ring 68 is provided with a pair of similarcircumferential lands 111, 113 of which the land 111 seals againstcommunication of compressed air along the shaft between the space 65 andthe air transfer chamber 91 and the land 113 seals against communicationbetween the two air transfer chambers 91 and 99.

On consideration of FIG. 1, it will be seen that the lengthwiseadjustment of the arbor to provide a bead set width in the presentembodiment of from 5 to 10 inches, is accomplished simply by selectingthe appropriate length of the shells 64a, 64b and sliding the primaryend ring and the parts attached thereto to abut the ends of the shellsselected. Only the shells need be exchanged; no other assembly ordisassembly of parts is required.

To maintain the desired axial length adjustment, in particular theselected bead set width, the shaft 12 has near each end a threadedsection 122 and a nut 124 threaded cooperatively thereon. Each nut canbe moved along its respective threaded section to secure the associatedend ring, and beadseating ring with their associated parts in placeaxially relative to the rib 59 and midplane 24. It will be readilyunderstood that the diameters of the threaded sections 122 and therespectively associated nuts 124 will differ in a usual manner tofacilitate assembly of the arbor.

The arbor 200, FIG. 2, in accordance with a further aspect of theinvention, has a center shaft 210 the description of which need not berepeated since it is identical in all significant respects to the shaft,FIG. 1. The arrangement of parts on the shaft 210, as in the arbor 10,is symmetrical with respect to a midplane 205 as well as the shaft axis207. It will, therefore, be understood that FIG. 2 represents, in amanner well understood in the related arts, a complete building arborthe complete showing of which would merely repeat the arrangement ofFIG. 2. The arbor also includes a pair of semi-cylindrical shells 212similar to the shells 64a, 64b described in connection with FIG. 1. Inthe present embodiment selected lengths of the shells 212 can becombined with selected spacers 214 more economically to provide a rangeof selectable bead set lengths.

The present arbor 200 differs from the previously described arbor 10 inthat there is disposed between the smooth cylindrical surface 216 of theshaft and the primary end ring 225 a shaft sleeve 232 having an outersmooth cylindrical surface 234 slidably fitted in the primary end ring225 as well as on the shaft 210. The sleeve 232 has three internalcircumferential lands 241, 243, 245 each of which accommodates a sealingO-ring. An air transfer chamber 247 is located axially between the lands241 and 243. Another airflow chamber 249 is formed between the lands 243and 245.

Each primary end ring 225 is disposed coaxially of the shaft sleeve 232and is fitted slidably thereto. Three circumferential lands 251, 253,255 each accommodates a seal slidably sealing the primary end ring tothe shaft sleeve. The two transfer chambers 257, 259 are formed,respectively, between the lands 251, 253 and between the lands 253, 255.Airflow communication is established to actuate the expandable sleeve264 by way of the passage 16' in the shaft 210 through the port 93' inthe shaft, the air transfer chamber 247, the port 266 in the wall of theshaft sleeve, the chamber 257, the port 268 in the primary end ring 225leading to the chamber 270 within the expandable sleeve.

Airflow communication for actuating the bladder 79" is established byway of passage 18', the shaft port 104', the air transfer chamber 249,the port 273 in the wall of the shaft sleeve, the air transfer chamber259 and the port 275 into the spacer 95' between the flanges 79"a, 79"bof the turnup bladder 79".

As in the previously described arbor the expandable sleeve 264 issecured across and circumferentially in the annular recess 282 by thesplit clamp rings 284 rigidly fixed to the primary end ring 225 tofunction as a part thereof. The gum rubber expandable beadseating ring286 circumferentially surrounds and is supported by the expandablesleeve 264. The forward edge portion 287 of the bladder is supported bythe radially outer surface of the clamp ring 288 so that the radiallyouter surface of the turnup bladder 79", the beadseating ring 286, thesplit clamp ring 284, the shells 212 and the spacer segments 214, whenused, are all at the uniform radial height with respect to the axis 207.

A particular feature is provided in the shape of the bead accommodatinggroove 291 extending circumferentially about the beadseating ring 286.This groove 291 is formed with a short side 291' forming approximately30 degrees with a plane normal to the axis and a longer side 291"disposed at an angle of about 80° to 85° with respect to the same plane.

The beadseating ring 286 is adhered to and made integral with theforward edge 287 of the turnup bladder 79", the flange 79"a of which issecured by the split ring clamp 288. The arrangement provides, asdescribed previously, that the beadseating ring when expanded by theexpandable sleeve 264 tends to expand to a greater circumference at itsedge axially inward of a bead thereon than it does at its axially outeredge adjoined to the bladder. This difference in the degree of expansiontends to rotate a typical axial cross-section of the ring 286 thus toexpand plies adjacent the bead thereon to a diameter at least slightlygreater than the inside diameter of the inextensible bead. As in thepreviously described arbor 10 this expansion of the seating ring 286 iscontrolled independently of the expansion of the turnup bladder itself.

Axially outwardly of the channel ring 95' the turnup bladder issupported by the cylindrical surface of the support sleeve 297, theflange 297' of which is secured to and made a part of the primary endring 225. The sleeve 297 serves also to clamp the respective flanges ofthe bladder to the primary end ring.

In the arbor, FIG. 2, it will be observed upon inspection of the drawingthat the axial adjustment capacity is increased considerably by the useof the additional pair of air transfer chambers provided by the shaftsleeve. This adjustment is effected without the need to employ flexibletubing in the drum to connect the expandable sleeve and the turnupbladder with the compressed air supply in the shaft. A part of the beadset length adjustment can be effected by manipulating the nut 296 on thethreaded section 298, moving the entire assembly a distancecorresponding to the axial length of the air transfer chambers relativeto the respective shaft ports without changing the axial relationbetween the primary end ring and the shaft sleeve. Additional, orindependent adjustment of bead set length can be accomplished similarlyby moving the primary end ring axially relative to the shaft sleeve bythe distance corresponding to the axial length of the air transferchambers. This is effected by providing an annular spacer 301 ofselected axial length between the face of the flange 303 on the shaftsleeve 232 and the opposing face of the primary end ring 225, and ofcourse substituting a cap screw of appropriate length for the cap screw305 illustrated.

The particular mechanical elements of the arbor 200 not described areidentical to or similar in structure and function to those described inconnection with the arbor of FIG. 1.

While certain representative embodiments and details have been shown forthe purpose of illustrating the invention, it will be apparent to thoseskilled in the art that various changes and modifications may be madetherein without departing from the spirit or scope of the invention.

What is claimed is:
 1. A building arbor for use in building a flexiblecylindrical article having at least one end portion turned or foldedabout an inextensible bead ring, which arbor in use is free ofrelatively moving metal parts, such arbor comprising a shaft, rigidcylindrical building surface having a multiplicity of perforationstherethrough, a circumferentially expandable elastomeric ring having aninflatable bladder attached integrally thereto and extending axiallyaway from said surface and disposed close to and at the same radiallevel as said surface, said expandable ring having a coaxial groove inits radially outward surface, an expandable sleeve secured to said shaftcoaxially of each expandable ring, an annular recess defining with saidexpandable sleeve an inflation chamber, said sleeve having a plane ofmaximum circumferential elongation midway between its circumferentialedges, said plane being axially inward of the associated expandable ringso that on being inflated the sleeve expands the expandable ring androtates each axial cross-section thereof angularly with respect to theshaft, thereby expanding more at its axially inward side than at itsaxially outward side relative to an inextensible ring disposedtherearound.